JPH01207260A - Production of 4,4'-methylenedianiline - Google Patents

Abstract

PURPOSE:To suppress production of highly condensed product and isomer and selectively obtain 4,4'-methylenedianiline in high yield, by reacting aniline with formaldehyde raw material in the presence of a fluorine-treated dealuminum Y type zeolite catalyst. CONSTITUTION:Aniline is reacted with formaldehyde raw material using a fluorine-treated dealuminum Y type zeolite as a catalyst at 20-300 deg.C for 0.1-40hr to provide the aimed product. The fluorine treated dealuminum Y type zeolite is a zeolite obtained by subjecting to Y type zeolite to dealuminum treatment and further subjecting the surface thereof to fluorine treatment and has 5.5-20 SiO2/Al2O3 (molar ratio) and 0.1-30wt.% fluorine content. The formaldehyde raw material is formaldehyde-containing raw material capable of reacting with aniline, e.g., formalin aqueous solution, trioxan or N,N- diphenylmethylenediamine.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention utilizes aniline and formaldehyde raw materials to produce 4,4
The present invention relates to a method for producing '-methylene dianiline.

[Conventional technology]

By reacting aniline and formaldehyde, 4.4'-
One method for producing methylene dianiline is to use a mineral acid such as hydrogen chloride as a catalyst.

This method requires more than the same molar amount of mineral acid as aniline,
In addition, an alkali of at least the same molar amount as the mineral acid is required for neutralization after the reaction, and 20 to 40% of high condensates such as polymethylene polyphenylamine are produced, resulting in the production of 4,4'-methylene dianiline. rate decreases.

In order to improve these drawbacks, a method using a solid acid catalyst has been developed, and Y-type zeolite has been proposed as a solid acid catalyst (Japanese Patent Publications No. 55-34138, No. 56-14104, No. 56-14104). 58-27261), the formation of high condensates cannot be suppressed, and 4.4'-
There is a problem that the yield of methylene dianiline is low.

[Problem to be solved by the invention]

[1] In order to solve the problems of the above-mentioned conventional methods, the present invention suppresses the formation of high condensates and isomers, and can selectively produce 4,4'-methylene dianiline in high yield. ,
The object of the present invention is to propose a method for producing 4,4'-methylene dianiline that can be used repeatedly as a catalyst.

[Means to solve the problem]

The present invention uses aniline and formaldehyde raw materials to produce 4,4
A method for producing 4,4'-methylene dianiline, which is characterized in that a fluorinated dealuminated Y-type zeolite is used as a catalyst.

The fluorine-treated dealuminated Y-type zeolite used as a catalyst in the present invention is a zeolite obtained by dealuminizing Y-type zeolite and further treating its surface with fluorine. Y-type zeolite is 5i02/Al□0. 5in4 and AL whose (molar ratio) is 2 to 5 and share oxygen atoms with each other
It has a three-dimensional framework structure consisting of tetrahedra of U, and the electrical balance of each tetrahedron containing aluminum is balanced by the presence of cations in the aluminosilicate skeleton.

Dealuminated Y-type zeolite is a dealuminated Y-type zeolite, and is 5i02/A.
1203 (molar ratio) is 5.5 to 20, and the crystal structure is almost the same as Y-type zeolite, but the size of the unit cell is generally contracted by about 1 to 2%. Examples of exchange cations include protons, alkaline earth cations, rare earth cations, and transition metal cations, with protons being preferred.

Y-type zeolite is generally SiO□/Al□0. The higher the molar ratio, the higher the acid strength, heat resistance, and acid/base resistance, but generally 5i02/Al□0. (molar ratio) exceeds 5, Y-type zeolite will not be produced, so S
Y with a raw material composition of iO,/Al□03 (molar ratio) of 2 to 5
After producing type zeolite, Y
While maintaining the basic crystal structure of type zeolite, Si
Efforts have been made to increase O□/Al□03 (molar ratio).

As such dealuminated Y-type zeolite, commercially available products can be used, such as Tosoh Kaku's TSZ-330HU.
A, TSZ-35011UA, TSZ-360HU
Examples include A (both are trademarks). In addition, for example, it can be prepared from Y-type zeolite 1 by the following method (D, 2).

■The first method is to remove aluminum by EDTA in the liquid phase.
For example, proton exchange type Y zeolite was added to a solution containing 1 to 10 times the weight of distilled water and 0.1 to 1 times the weight of EDTA and left for 10 to 200 hours. After that, 0.5 to 3 times the weight of 1 to 3N HCI was added dropwise thereto, and the temperature was heated to 100°C while stirring.
After stirring for 1 to 10 hours, the solid phase is separated by filtration or centrifugation, washed with water, and then calcined at 300 to 700°C for 1 to 10 hours in air or under a nitrogen atmosphere. be.

(The second method is a steam treatment method under high temperature. For example, for proton exchange type Y zeolite in a fixed bed, 60%
10-100 with nitrogen in the temperature range of 0-900℃
After processing for 1 to 10 hours using steam diluted to Alternatively, proton exchange type Y zeolite is heated at 600 to 900°C under normal pressure or pressurized conditions in a fluidized bed.
After treatment for 1 to 10 hours using steam diluted to 10 to 100% with nitrogen at a temperature range of approximately 10 to 100%
This method involves washing with twice the weight of distilled water and firing at 300 to 700°C for 1 to 10 hours in air or under a nitrogen atmosphere.

Fluorine-treated dealuminated Y-type zeolite is obtained by fluorine-treating the above-mentioned dealuminated Y-type zeolite to bond fluorine within the crystal structure, and is 5i02/
Al□03 (molar ratio) is 5.5 to 20, and fluorine content is 0.1 to 30% by weight. The exchanged cation is a proton,
Examples include alkaline earth cations, rare earth cations, and transition metal cations, but protons are preferred. Proton exchange type fluorine treated dealuminated Y-type zeolite is X in Table 1.
It has a line diffraction pattern and has a different crystal structure from dealuminated Y-type zeolite and fluorine-treated Y-type zeolite.

Table 1 Diffraction angle (20°) Relative intensity 6.4±0.2 90~100 10.4±0.2' 60~80 12.1+0
．． 2 40~70 14.8±0.21~30 16.0±0.2 70~90 19.1±0.2 to~40 20.8±0.2 20~50 23.3±0.21 ~20 24.2±0.2 20~50 25.2±0.21~30 27.6±0.2 10~30 Note) X-ray diffraction analysis was performed using α rays for Cu. Set.

However, the relative intensity of the diffraction line of 6.4±0.2 is assumed to be 100.

The fluorine-treated dealuminated Y-type zeolite can be obtained by contacting the above-described dealuminated Y-type zeolite with a fluorine-containing compound. Examples of fluorine-containing compounds include ammonium fluoride, tetramethylammonium fluoride, tetraethylammonium fluoride, methylammonium fluoride, dimethylammonium fluoride, and other ammonium fluoride compounds; sodium fluoride, hydrogen fluoride, boron trifluoride, and monofluoride. Acetic acid, CFCI, CF2C
l□, CF, C1, CF4. CHFC1m, Cll
F2C1,CHF,,CFCI,-CFCI2,CF
2Cl-CF2Cl, CF2C1-CF, CF, -C
F,,CH,-CF2C1,CH,-CIIF,,CF
, Br, CF2Br-CF2Br, HF, SF4.
Examples include fluorine compounds such as 3FBF.

As a fluorine treatment method, for example, dealuminated Y-type zeolite is treated with 0. After immersion in an aqueous solution of a fluorine-containing compound containing 1 to 30% by weight of O for 0.01 to 24 hours, the solid phase is separated by filtration or centrifugation and calcined at 300 to 800°C in air or under a nitrogen atmosphere. Another method is to bring dealuminated Y-type zeolite into contact with a gaseous fluorine-containing compound at a temperature of 0 to 800°C, preferably 200 to 600°C. and then, after bringing the reaction tube to a predetermined temperature, the gaseous fluorine-containing compound is supplied to the reaction tube for a predetermined period of time (for example, 0.1 to 10 hours, preferably 0.5 to 2 hours). , contacting the dealuminated Y-type zeolite with the gaseous fluorine-containing compound described above;
Thereafter, if necessary, the fluorine-containing compound remaining in the reaction tube is removed by replacing it with an inert gas such as nitrogen, or by degassing it under reduced pressure.

The method for producing 4,4'-methylene dianiline of the present invention is as follows.

Aniline and formaldehyde raw materials are reacted using such fluorine-treated dealuminated Y-type zeolite as a catalyst.

In the present invention, the formaldehyde raw material is a raw material containing formaldehyde that reacts with aniline, and is obtained by mixing formalin aqueous solution, trioxane, paraformaldehyde, dialkoxymethane such as dimethoxymethane, and aniline and formalin aqueous solution without a catalyst. Examples include N,N'-diphenylmethylenediamine. Among these, when N,N'-diphenylmethylenediamine and dialkoxymethane are used as raw materials, water is not produced in the reaction, so the selectivity and activity of 4,4'-methylenedianiline are higher than other raw materials, and these are preferred.

The aniline/formaldehyde charging ratio in the reaction is 1 to
100, preferably 2-50. More preferably 3 to 2
It is 0.

The catalyst is preferably in the form of powder or pellets, and the catalyst concentration is 1 to 100% by weight, preferably 5 to 40% by weight, based on the reaction mixture.

The reaction is preferably carried out in a liquid phase, in which case the reaction may be carried out without a solvent, but it is also possible to carry out the reaction using a solvent. Examples of solvents include aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as pentane, hexane, heptane, octane, nonane, decane, cyclohexane, and decalin; dichloromethane, chloroform, and tetracarbonated carbon%H.
, AF and halogenated hydrocarbons.

A preferred reaction method is to contact the aniline with the catalyst, and then
There is a method in which a formaldehyde raw material such as a formalin aqueous solution is added and reacted, and a method in which aniline and a formaldehyde raw material such as a formalin aqueous solution are mixed in the absence of a catalyst to form a condensate, and the aqueous phase is separated and then brought into contact with a catalyst. .

Reaction temperature is 20-300℃, preferably 30-180℃
, more preferably 50 to 140°C. The pressure may be normal pressure, but it may be pressurized with an inert gas or the like to maintain the liquid phase. Reaction time is 0.1 to 40 hours, preferably 0
．． It takes 3 to 5 hours. The reaction method may be a batch method using a liquid phase, a semi-batch method using a liquid phase, or a continuous method using a fixed bed.

〔Effect of the invention〕

According to the present invention, since fluorinated dealuminated Y-type zeolite is used as a catalyst, the formation of high condensates and isomers is suppressed, and 4,4'-methylene dianiline can be selectively produced in high yield. In addition, there is little deactivation of the catalyst, and the catalyst can be used repeatedly.

〔Example〕

Examples of the present invention will be described below.

Reference Example 1 [Catalyst Preparation] Proton exchange dealuminated Y-type zeolite TSZ-
33011tlA (manufactured by Tosoh Corporation, trademark, 5in2
/ At□0゜ (molar ratio) = 5.5 to 6.5) 5.0
g to 2.5% by weight ammonium fluoride aqueous solution 100+n
After stirring at 50°C for 1 hour, solid matter was filtered, dried at 100°C for 12 hours, and further stirred at 600°C.
Calcinate for 3 hours to make fluorine-treated dealuminated Y-type zeolite 1! )is. The physical properties are shown in Table 2.

Reference Example 2 [Catalyst Preparation] In Reference Example 1, the concentration of ammonium fluoride aqueous solution was 1.25.
A fluorine-treated dealuminated Y-type zeolite was obtained by carrying out the same operation except that the weight percent was changed.

The physical properties are shown in Table 2.

Table 2 Crystal structure Table 3 Table 4) Ammonia temperature-programmed deM? A (After adsorbing ammonia at 100°C, the temperature is raised to 700°C to desorb and quantify the ammonia) Diffraction angle (20°) Relative intensity 6.4 100 10.4 70 12, L55 14. 8 15 16.0 80 19.1 25 20.8 35 23.3 5 24.2 35 25.2 10 26.4 5 27.6 20 Diffraction angle (2θ°) Relative intensity 6.3 100 10.3 70 12.160 15.9 90 19.0 30 20.7 40 23.2 10 24.0 55 26.2 5 27.5 30 Example 1 400.4 g of aniline and 37% by weight formalin water 69.
Mix 8 g at room temperature and stir for 5 hours. After that, after leaving it overnight, separate the aqueous layer and heat it at 50℃ using a rotary evaporator.
300mm 11g N by dehydrating for 4 hours under reduced pressure
, N'-methylene dianiline/aniline mixture was obtained.

The structure was confirmed by 1jCNMH, and it was found that 100% of formaldehyde had reacted to form N,N'-diphenylmethylenediamine.

Next, add N to a fourth 25 mQ flask equipped with a reflux condenser.
2 at room temperature under N,N'-diphenylmethylenediamine/
Add 2.5 g of aniline mixture and 0.5 g of fluorine-treated dealuminated Y-type zeolite of Reference Example 2, and heat to 120°C.
The reaction was carried out for 30 minutes. After cooling to room temperature, the supernatant was taken out and separated from the catalyst, and a portion of the supernatant was analyzed by GC and GPC.

2.5 g of N,N'-diphenylmethylenediamine/aniline mixture was added to the separated catalyst, and the same operation as above was repeated three times.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the proton-exchange dealuminated Y-type zeolite used in the reference example before fluorine treatment was used as a catalyst.

The above results are shown in Table 5.

From the above results, the example has a higher aniline conversion rate and 4,4'-methylene dianiline selectivity than the comparative example, has less catalyst deactivation, and can be used repeatedly. It turns out that it is possible.

Example 2 2.5 g of N,N'-diphenylmethylenediamine/aniline mixture prepared in the same manner as Example 1 and 0.5 g of the fluorinated dealuminated Y-type zeolite of Reference Example 2
was reacted at 120°C for 3 hours in the same manner as the first time in Example 1. The results of the reaction are shown in Table 6.

Example 3 Example 2 except that the zeolite of Reference Example 1 was used as the catalyst
I did it in the same way. The results of the reaction are shown in Table 6.

Heijo I Nehosho 4F March 22, 1988 1, Display of the case 1988 Patent Application No. 32551 2, Title of the invention 4. Process for producing 4'-methylene dianiline 3, Person making the amendment Case and Relationship Patent applicant representative Shogo Takebayashi

Claims (3)

[Claims] (1) 4,4'- from aniline and formaldehyde raw materials
1. A method for producing 4,4'-methylene dianiline, characterized in that a fluorinated dealuminated Y-type zeolite is used as a catalyst. (2) The method according to claim 1, wherein the formaldehyde raw material is an aqueous formalin solution, trioxane, or N,N'-diphenylmethylenediamine. (3) Fluorine-treated dealuminated Y-type zeolite is Si
The method according to claim 1 or 2, wherein the O_2/Al_2O_3 (molar ratio) is 5.5 to 20 and the fluorine content is 0.1 to 30% by weight.